Strip http:// or https:// From a String, Optionally Removing www.

This function takes a string and returns a copy with all occurrences of http:// and https:// removed. The string, "Please visit http://example.com to find out more" would convert to "Please visit example.com to find out more". Generally this is more compact as the http:// is redundant when you are obviously referring to a URL.

Optionally, this function can also strip the www subdomain by passing true as the second parameter. It's set to false by default as example.com and www.example.com could theoretically contain different websites.